Various types of storage devices are available to store data for electronic devices. Examples of storage devices include tape-based storage devices, disk-based storage devices, integrated circuit (IC) storage devices, and others.
In a tape-based storage device, data is stored on plural data tracks of a storage tape, where the data tracks extend generally longitudinally along the storage tape. The reading and recording of data in the data tracks is accomplished by using tape heads, which typically include magnetic read/write heads for reading/recording data on magnetic storage tapes.
The storage tape is moved longitudinally with respect to the tape head as the recording operation or read operation proceeds. When reading from or writing to a storage tape, accurate lateral positioning of the tape head is desirable. To achieve accurate lateral positioning of the tape head, servo bands (or servo tracks) are recorded onto the storage tape. The servo bands contain servo patterns that are detectable by the tape head during read/write operations for determining the lateral position of the tape head with respect to the storage tape.
Other types of storage media also contain servo tracks, including disk-based storage media.
With new generations of storage media, storage capacities are increased by using smaller spacings between data tracks on the storage media. As a result, accurate positioning of read or write heads over data tracks of the storage media have become more difficult due to the decreased spacings between data tracks.
As spacings between data tracks become smaller, sources of positioning error of read or write heads with respect to the data tracks that were previously negligible (when used with storage media having larger spacings between data tracks) may become a source of positioning error that cannot be disregarded.